Acoustic echo cancellation is important for audio teleconferencing when concurrent communication (or full-duplex transmission) of speech is necessary…

Introduction

In acoustic echo cancellation, a measured microphone signal d(n) contains two signals:

  • the near-end speech signal v(n)
  • the far-end echoed speech signal dhat(n)

The main goal is to remove the far-end echoed speech signal from the microphone signal so that only the near-end speech signal gets transmitted.

The Room Impulse Response

First, we tend to describe the acoustics of the loudspeaker-to-microphone signal path wherever the speakerphone is located. We can use a protracted finite impulse response filter to explain these characteristics. The subsequent sequence of commands generates a random impulse response that’s not unlike what a conference room would exhibit assuming a system sampling rate of fs = 16000 Hertz.